According to Jungian Jolande Jacobi, in psychic inner reality the archetypal Shadow is a symbol for an aspect of the self (1959). When we cannot find a way to work with our shadow through our dreams or in other ways, it becomes a symptom in our outer world.
Jungian therapist and author Jeremiah Abrams says our personal shadow came into play when we were about two years old. When as little children we were not allowed to be ourselves, our egos were not able to make conscious and integrate certain parts of us. As a survival mechanism during our developmental years, certain aspects of our nature had to be repressed, hidden away through denial. And there they remain in our subconscious to "cook." Psychic energy has no place to go when repressed; like a pressure cooker it builds, causing tension and stress--even physical disease (Abrams 1990).
Until it is made conscious, the shadow causes us to create emotional explosions and catastrophe or to explode in emotionalism. It stands there at the threshold of our unconscious mind, reflecting back to us our blind side. We must learn to embrace the shadow without trying to win it over. It is our teacher. Often we aren't even able to hear the more kindly offerings from our friends, so to command our attention the shadow must pop out and remind us that it exists from time to time.
The shadow is emotional in nature, not a "thing" or a certain "person" we can ever know concretely. It is often made up of our aggressive or sexual urges and promptings from the extremes, or some other "untamed" aspect of our human/animal nature. Since our rage and sexual desire are two aspects of human nature we have the hardest time integrating and respect the least, they are often the aspects of us that operate in shadowy ways.
According to Jungian Marie-Louise von Franz, the shadow takes the form of laziness, greed, envy, jealousy, the desire for prestige, aggressions, and similar "tormenting spirits" (1980: 123). When we ignore our shadow, it is like opening a door and allowing negative powers such as wrath, hatred, envy, lechery, or faintheartedness to step in. In ancient times, these were known as demons or bad spirits (von Franz, 1980: 116.).
When we try to deny the shadow it multiplies. When we choose to integrate it instead, we gain stability and expansion of consciousness, losing our one-sided self-righteousness and becoming flexible instead of defensive and rigid. If your shadow seems to you to be fairly hard to accept, or you're having trouble finding it at all, you may want to ask for the help of a good therapist who is as at home in the shadow's domain as in the light, acquainted with the wilderness experience we humans must travel through if we are to realize our full potential. Jung writes:
Everyone carries a shadow, and the less it is embodied in the individual's conscious life, the blacker and denser it is. At all counts, it forms an unconscious snag, thwarting our most well-meant intentions.
Embracing Our "Sparring Partner": The Personal Shadow
If you're brave enough to undergo the task alone, knowing you have a great deal of ego strength, you can ask your shadow to show itself to you through inner work, using imagery or other methods that access your unconscious mind. You can go within and talk with your shadow in the silence of your mind anytime it constellates and begins to bother you. Or you can keep a "shadow journal" and write letters to it, letting it respond to you. Tell it you will accept it, no matter what. And that you will hold it in your heart.